It's a deep-breath moment in the history of technology as Solar Impulse soars to the skies.

Because, pinch yourself, solar power is predicted to become the dominant source of electricity globally by 2050.

The price of solar electric panels fell 70% in recent years and costs are expected to halve again this decade.

And Deutsche Bank forecasts that, based on current fossil fuel prices, solar will produce power as cheaply as gas in two thirds of the world before 2020.

In the UK the solar industry thinks it can compete with wind within 18 months and with gas in the near future. In the USA, solar jobs already outnumber coal jobs.

The solar revolution was sparked by government subsidies, which attracted venture capitalists to fund innovation and created a huge market that Chinese manufacturers are battling to exploit.

The solar boom is a huge help in the battle against climate change, but scientists warn it's not nearly enough. And we must find ways of storing that mighty but capricious power, and making it work with the grid.